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Polarization Observables T and F in Single 0 and -Photoproduction off Quasi-Free Nucleons Thomas Strub, A2 Collaboration University of Basel 28th August 2014, PANIC 2014 A 2 Outline Motivation Experimental Setup Polarization

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SLIDE 1

Polarization Observables T and F in Single π0 and η-Photoproduction

  • ff Quasi-Free Nucleons

Thomas Strub, A2 Collaboration

University of Basel

28th August 2014, PANIC 2014

2 A

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SLIDE 2

Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Outline

1 Motivation 2 Experimental Setup 3 Polarization Observables 4 Analysis Methods 5 Selected Results 6 Conclusion

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Motivation

Problems on experimental side

◮ Nucleons’ excitation spectrum is a complicated overlap of many short

lived, broad resonances

◮ Cannot be understood from differential cross sections alone

Problems on theory side

◮ QM predicts more states than observed (missing resonances) ◮ Perturbative QCD cannot be applied in this energy region ◮ Lattice gauge QCD cannot (yet) reproduce all desired properties

1000 1200 1400 1600 1800 2000 2200 2400 P11(939) P11(1440) D13(1520) S11(1535) S11(1650) D15(1675) F15(1680) D13(1700) P11(1710) P13(1720) P13(1900) F17(1990) F15(2000) D13(2080) S11(2090) P11(2100) G17(2190) D15(2200) H19(2220) G19(2250) P33(1232) P33(1600) S31(1620) D33(1700) P31(1750) S31(1900) F35(1905) P31(1910) P33(1920) D35(1930) D33(1940) F37(1950) F35(2000) S31(2150) H39(2300) D35(2350) F37(2390) H3,11(2420)

Mass/(MeV/c2)

N(I=1/2) ∆(I=3/2) exp exp QM QM

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Motivation

Solution

◮ Effective quark models ◮ Experiment delivers observables to fix the models parameters via PWA

Polarization observables from meson photoproduction

◮ Probing spin degrees of freedom ◮ Unique PWA solution

= ⇒ Need 8 (of 16) carefully chosen observables for complete experiment

◮ Include angular momentum L ≤ 3, i.e., S, P, D, F-wave

= ⇒ Need full angular coverage, high precision measurements Proton and neutron channel

◮ Probe isospin degree of freedom ◮ Isospin decomposition into AV 3, AIV , AIS for π photoproduction A(γp → π+n) = −

  • 1

3AV 3 +

  • 2

3

  • AIV − AIS

A(γp → π0p) = +

  • 2

3AV 3 +

  • 1

3

  • AIV − AIS

A(γn → π0n) = +

  • 1

3AV 3 −

  • 2

3

  • AIV + AIS

A(γn → π−p) = +

  • 2

3AV 3 +

  • 1

3

  • AIV + AIS

= ⇒ At least one measurement off the neutron needed.

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Motivation

Special case η photoproduction

◮ Isospin I = Iz = 0. ◮ No isospin changing current (AV 3 = 0) A(γp → ηp) = AIS + AIV A(γn → ηn) = AIS − AIV

= ⇒ only N∗(I = 1

2) resonances contribute ◮ Recent results show a narrow structure

around 1670 MeV Photoproduction off the neutron

◮ Neutron bound in nucleus

= ⇒ quasi free neutron

◮ Correct treatment of Fermi motion ◮ Comparison of free and quasi free

proton data (can differ due to FSI)

P11(939) P11(1440) D13(1520) S11(1535) S11(1650) D15(1675) F15(1680) D13(1700) P33(1232) P33(1600) S31(1620) D33(1700)

1000 1200 1400 1600

Mass [MeV/c2]

N(I=1/2) (I=3/2)

  • Notation:

L2I2J ; L=0(S),1(P),2(D),...

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Experimental Setup Experimental Setup

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

MAinzer MIcrotron

High quality electron beam

◮ Energy up to 1.5 GeV ◮ Intensity up to 100 µA ◮ Polarization ≈ 80%

Bremsstrahlung photons

◮ 1/Eγ distribution ◮ Photon polarization: Olsen

maximum function

Photon Energy 200 400 600 800 1000 1200 1400 Polarization degree 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Crystal Ball/TAPS @ MAMI

CB

◮ PID ◮ MPWC ◮ NaI crystals

TAPS

◮ BaF2/PWO crystals ◮ Veto wall

= ⇒ Almost 4π acceptance

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Polarization Observables Polarization Observables

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

General Formula

General decomposition of dσ into 16 polarization observables reads

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Definition of T and F

◮ Target asymmetry T

= ⇒ Transversally polarized target PT = PT

x = 0 ◮ Double polarization observable F

= ⇒ Transversally polarized target PT = PT

x = 0

Circularly polarized photon beam Pγ = Pγ

c = 0 ◮ For

PR = 0 (unpolarized recoil), Pγ = Pγ

c (circular photon polarization)

and PT = PT

x (transverse target polarization) the general decomposition

reduces to dσ( Pγ, PT, 0) = 1 2dσ0

  • 1 + TPT

y + FPγ c PT x

  • = 1

2dσ0

  • 1 + T|PT| cos(φ′) + F|Pγ||PT| cos(φ)
  • .

◮ Observables T and F manifest themselves by a cosine-φ(′)-modulated

unpolarized cross-section

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Definition of T and F (experimental approach)

T and F can be rewritten as T cos(φ′) = 1 PTPγ dσ↑(φ′) − dσ↓(φ′) dσ↑(φ′) + dσ↓(φ′), where (↑, ↓) denotes the target polarization state, F cos(φ) = 1 PTPγ dσ−(φ) − dσ+(φ) dσ−(φ) + dσ+(φ), where (+, −) denotes the photon helicity state. Here, F = F(E, θ), T = T(E, θ), PT = PT(t) and Pγ = Pγ(E γ, PB(t))

◮ Symmetric contributions cancel in the

numerator

◮ Denominator equals unpolarized dσ ◮ φ = Angle between target

polarization vector and production plane

◮ φ′ = Angle between target

polarization vector and normal to production plane

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Methods to extract T and F

Polarized target: D-butanol (C4D9OD)

◮ Only deuterons are polarized ◮ Carbon/oxygen contribution vanish in numerator

Two methods can be used:

◮ 1. Normalize with deuterium target

A cos(φ) = 1 PTPγ dσ−

DB(φ) − dσ+ DB(φ)

dσ−

D (φ) + dσ+ D(φ)

= ⇒ Needs flux and efficiency correction of count rates.

◮ 2. Normalize with D-butanol target

A cos(φ) = 1 PTPγ dN−

DB(φ) − dN+ DB(φ)

dN−

DB(φ) + dN+ DB(φ) · d

= ⇒ No need for flux and efficiency correction, but dilution factor d, i.e., d = 1 + dσ0

C

dσ0

DB

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Analysis Methods Analysis Methods

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Event selection

◮ Event selection

◮ Full exclusive on proton (neutron as spectator)

γ + d − → π0 + p(n) − → 2γ + p(n) 2 neutral, 1 charged γ + d − → η + p(n) − → 2γ + p(n) 2 neutral, 1 charged γ + d − → η + p(n) − → 3π0 + p(n) − → 6γ + p(n) 6 neutral, 1 charged

◮ Full exclusive on neutron (proton as spectator)

γ + d − → π0 + n(p) − → 2γ + n(p) 3 neutral, 0 charged γ + d − → η + n(p) − → 2γ + n(p) 3 neutral, 0 charged γ + d − → η + n(p) − → 3π0 + p(n) − → 6γ + n(p) 7 neutral, 0 charged

◮ Determination of the neutron candidate by χ2-test. ◮ Invariant mass cut on all 3 π0 from η → 6γ decay.

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Applied Cuts

All cuts are determined from LD2 target for all θ and energy bins.

◮ Coplanarity cut

∆φ = 180◦ − |φmeson − φrecoil|

◮ Invariant mass cut

∆mmeson = |Pµ

meson| − mtheo. meson ◮ Missing mass cut

∆MM = |Pµ

γ + Pµ nucleon − Pµ meson| − mtheo nucleon

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Reconstruction of Kinematics

Transfer kinematics into CM frame

◮ Fermi momentum from deuterium (carbon/oxygen) target

= ⇒ Initial state not determined

◮ Reconstruction of nucleons Fermi momentum from final state, i.e., solve

Pµ

γ + Pµ nucleon = Pµ meson + Pµ recoil

for Pµ

nucleon. ◮ Have enough information to reconstruct Fermi momentum of nucleon.

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Determination of Dilution Factor

◮ Determination of the dilution factor from missing mass spectra ◮ Carbon + x Deuterium = Sum ≈ D-butanol

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

TOMultiPad_Dummy_0

Entries Mean RMS 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

TOMultiPad_Dummy_1

Entries Mean RMS 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

TOMultiPad_Dummy_2

Entries Mean RMS 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

TOMultiPad_Dummy_3

Entries Mean RMS 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

TOMultiPad_Dummy_4

Entries Mean RMS 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

TOMultiPad_Dummy_5

Entries Mean RMS 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

TOMultiPad_Dummy_6

Entries Mean RMS 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

TOMultiPad_Dummy_7

Entries Mean RMS

  • 200
  • 200
  • 200
  • 200

200 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

  • p [MeV]

η MM counts [a.u.]

◮ Dilution factor d = 1 +

  • MMcut ∆MMcarbon /
  • MMcut ∆MMdeuterium

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Selected Results Selected Results (preliminary)

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

T and F for Single π0 Photoproduction (preliminary)

Invariant mass W [MeV] 1200 1300 1400 1500 1600 1700 1800 1900 Asymmetry F

  • 1
  • 0.5

0.5 1 0.067 ± ) = 0.000 θ cos(

free proton (V. Kashevarov) q.f. proton SAID MAID

Invariant mass W [MeV] 1200 1300 1400 1500 1600 1700 1800 1900 Asymmetry F

  • 1
  • 0.5

0.5 1 0.067 ± ) = 0.000 θ cos(

q.f. neutron q.f. proton SAID neutron MAID neutron SAID proton MAID proton

Invariant mass W [MeV] 1200 1300 1400 1500 1600 1700 1800 1900 Asymmetry T

  • 1
  • 0.5

0.5 1 0.067 ± ) = 0.000 θ cos(

free proton (V. Kashevarov) q.f. proton SAID MAID

Invariant mass W [MeV] 1200 1300 1400 1500 1600 1700 1800 1900 Asymmetry T

  • 1
  • 0.5

0.5 1 0.067 ± ) = 0.000 θ cos(

q.f. neutron q.f. proton SAID neutron MAID neutron SAID proton MAID proton

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

T and F for η Photoproduction (preliminary)

Invariant mass W [MeV] 1450 1525 1600 1675 1750 1825 1900 Asymmetry F

  • 0.6
  • 0.4
  • 0.2

0.2 0.4 0.6 0.8 0.167 ± ) = -0.167 θ cos(

free proton (V. Kashevarov) q.f. proton MAID proton BnGa proton

Invariant mass W [MeV] 1450 1525 1600 1675 1750 1825 1900 Asymmetry F

  • 0.6
  • 0.4
  • 0.2

0.2 0.4 0.6 0.8 0.167 ± ) = -0.167 θ cos(

q.f. neutron q.f. proton MAID neutron MAID proton BnGa neutron BnGa proton

Invariant mass W [MeV] 1450 1525 1600 1675 1750 1825 1900 Asymmetry T

  • 0.6
  • 0.4
  • 0.2

0.2 0.4 0.6 0.8 0.167 ± ) = -0.167 θ cos(

free proton (V. Kashevarov) q.f. proton MAID proton BnGa proton

Invariant mass W [MeV] 1450 1525 1600 1675 1750 1825 1900 Asymmetry T

  • 0.6
  • 0.4
  • 0.2

0.2 0.4 0.6 0.8 0.167 ± ) = -0.167 θ cos(

q.f. neutron q.f. proton MAID neutron MAID proton BnGa neutron BnGa proton

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Conclusion

Conclusion

◮ Preliminary results for T and F for single π0- and η photoproduction off

quasi free nucleons

◮ Very good agreement with free proton data ◮ Models fail for ...

... higher energies ... the neutron channel ... the η channel Outlook

◮ Use full statistic (here: π0 ≈ 70%, η ≈ 50%) ◮ Observables for double meson photoproduction ◮ Final results will contribute to the ’complete experiment’

= ⇒ Possible impact on models

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

Thanks Thank you for your attention.

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

F: ηp

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.833 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.500 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.167 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.167 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.500 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.833 θ cos( 1450 1525 1600 1675 1750 1825 1450 1525 1600 1675 1750 1825 1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

  • 0.4

0.2

W [MeV] Asymmetry F

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

F: ηn

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.833 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.500 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.167 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.167 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.500 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.833 θ cos( 1450 1525 1600 1675 1750 1825 1450 1525 1600 1675 1750 1825 1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

  • 0.4

0.2

W [MeV] Asymmetry F

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

T: ηp

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.833 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.500 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.167 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.167 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.500 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.833 θ cos( 1450 1525 1600 1675 1750 1825 1450 1525 1600 1675 1750 1825 1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

  • 0.4

0.2

W [MeV] Asymmetry T

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

T: ηn

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.833 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.500 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = -0.167 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.167 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.500 θ cos(

1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

0.167 ± ) = 0.833 θ cos( 1450 1525 1600 1675 1750 1825 1450 1525 1600 1675 1750 1825 1450 1525 1600 1675 1750 1825 1900

  • 0.4

0.2 0.8

  • 0.4

0.2

W [MeV] Asymmetry T

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

F: π0p

1200 1550 1900

  • 1

1 0.067 ± ) = -0.933 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.800 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.667 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.533 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.400 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.267 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.133 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.000 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.133 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.267 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.400 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.533 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.667 θ cos(

1200 1550 1200 1550 1200 1550

  • 1

1

  • 1
  • 1

W [MeV] F

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

F: π0n

1200 1550 1900

  • 1

1 0.067 ± ) = -0.933 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.800 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.667 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.533 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.400 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.267 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.133 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.000 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.133 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.267 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.400 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.533 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.667 θ cos(

1200 1550 1200 1550 1200 1550

  • 1

1

  • 1
  • 1

W [MeV] F

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

T: π0p

1200 1550 1900

  • 1

1 0.067 ± ) = -0.933 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.800 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.667 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.533 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.400 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.267 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.133 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.000 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.133 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.267 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.400 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.533 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.667 θ cos(

1200 1550 1200 1550 1200 1550

  • 1

1

  • 1
  • 1

W [MeV] T

Polarization Observables T and F Thomas Strub, A2 Collaboration

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Outline Motivation Experimental Setup Polarization Observables Analysis Methods Selected Results Conclusion

T: π0n

1200 1550 1900

  • 1

1 0.067 ± ) = -0.933 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.800 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.667 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.533 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.400 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.267 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = -0.133 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.000 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.133 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.267 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.400 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.533 θ cos( 1200 1550 1900

  • 1

1 0.067 ± ) = 0.667 θ cos(

1200 1550 1200 1550 1200 1550

  • 1

1

  • 1
  • 1

W [MeV] T

Polarization Observables T and F Thomas Strub, A2 Collaboration